Abstract: An automatic programmable logic controller (PLC) control system of heat treatment of infected wood were designed, aiming at the heat treatment of pine wood nematode infected timber and wood drying process, and formulate the heat-treatment and drying process. The heat-treatment and drying parameter of the online measurement and automatic control were realized and the intelligent management system as well as control system software were developed. The system datas are as follows: measuring temperature range -40-125℃, accuracy ±1℃, relative humidity 30%-100% with accuracy ±2% RH. The accuracy was ±1.5% when wood moisture content between 8%-30%, and accuracy was ±3% at range 30%-80%. The results showed that this system had higher reliability, guarantee the quality of insecticide treatment, improved heat treatment equipment performance.